1. Field of the Invention
This invention relates to tubular inflatable bladders constructed of multiple plies of rubber and fabric reinforced rubber, and to a method of making the same. In particular, the end construction of such bladders and the method of sealing the ends, and has particular application to the construction of two part, annular inflatable brakes and clutches.
2. Prior Art
A type of brake, used for instance on tire building machines, comprises an inflatable, annular bladder which surrounds a rotatable shaft. The bladder is built up from several layers of flat rubber sheets, some of which are fabric reinforced, folded to form a multiple ply torroid which is flattened in the radial direction. The bladder is contained within a rigid ring such that introduction of compressed air into the bladder causes it to expand radially inward against the shaft to generate a braking force.
This type of brake only has one moving part, the expandable bladder. It adjusts readily to minor misalignments and to wear, needs little attention, and is easily controlled. This type of device is also useful as a clutch for selectively coupling the shaft to another rotating part such as a drum.
One difficulty with this type of brake when used on a tire building machine is that the entire drum shaft must be pulled in order to change a leaking brake. This requires a good deal of down time, and a time consuming "dial-in" after the drum has been reinstalled.